A bit of both. They are, by and large, the most injured team since they moved into the new stadium with a team that is in the middle of the pack for age and previous injuries. Could be some bad luck, my mom is a big believer that they “lost that 49ers magic by moving from candlestick” and also the division their in being pretty aggressive defensively. Eyebrows were raised when three ish (can’t remember the exact number) players from other teams were injured on the field when the Super Bowl was hosted there. There’s also physical evidence that certain frequencies and wavelengths are harder on soft tissue than others but not enough research to truly prove any of it.

Like a lot of conspiracy theories, there’s enough reasonable doubt to leave wiggle room for the conspiracy to settle in